Copyright, 1925, by
THE SOLVAY PROCESS COMPANY
Syracuse, New Yom
The Use of Solvay Calcium Chloride
Comparative strength ratios
Cold weather use
Directions for using Solvay Calcium Chloride
Amount to be used and cost
The Salvador Rodriguez Memorial Building at Tampa, Florida. Concrete plays a large
part in this type of construction. Solvay Calcium Chloride was used to the complete
satisfaction of the architect, builders and owners.
URING the last decade there has probably been no
more important development in concrete construc-
tion than the use of Calcium Chloride for attaining a
rapid set and early strength.
The purpose of this booklet is to present the results ob-
tained by The Solvay Process Company through experi-
ments and practical experience, indicating the value of
Calcium Chloride as an essential product in modern con-
Within the past few years there has been a constantly
increasing demand on the part of architects, engineers and
contractors for a material or process which would accelerate
the hardening of concrete; which would give it early
strength, and at the same time not affect the final setting of
the concrete — the most desirable accelerator being the one
which would hasten the hardening, and still not adversely
affect the final setting.
THE USE OF CALCIUM CHLORIDE
WITH PORTLAND CEMENT
Exhaustive tests have thoroughly proven that the ma-
terial which best meets these necessary and important re-
quirements is Solvay Calcium Chloride.
It not only gives early strength and hardness to concrete,
but at the same time densities, makes it more water-proof
and aids the concrete to resist freezing at winter tempera-
Solvay Calcium Chloride is a white, dry, flaky chemical,
extremely hygroscopic and dissolves almost instantly in
VALUABLE RESULTS THOROUGHLY PROVEN
That the use of Calcium Chloride with Portland Cement
is beneficial has been thoroughly established as a result of
the extensive tests made by the United States Bureau of
Standards, American Society for Testing Materials, Port-
land Cement Association, United States Engineers, Lewis
Institute and The Solvay Process Company.
The first important investigation in this connection was
conducted some years ago by the Bureau of Standards co-
operating with the United States Engineers' office, Mem-
phis, Tennessee. Tests were made with many different
Of these, only Calcium Chloride showed any beneficial
results. In the Standard Mortar Test, made with 3 :i Ottawa
Sand, it was found that the addition of 2 per cent, to 4 per
cent. Commercial Calcium Chloride (by weight of the mix-
ing water) increased the tensile strength from 155 per cent,
to 230 per cent, by the end of 24 hours, and from 173 per
cent, to 190 per cent, at the end of 48 hours, without affect-
ing adversely the initial set of the mixture.
During the past two years a subcommittee of Committee
C-9 of the American Society for Testing Materials has con-
ducted a cooperative series of tests on accelerators of the
Calcium Chloride type. These tests, without exception,
show a marked increase in early strength of cement mortar
which contains 2 per cent, to 3 per cent. Calcium Chloride.
Thousands of tests have been made by many different
organizations, and while there are some variations in re-
sults, due to different brands of cement, kinds of aggregate,
and other variable factors, a summary of the tests shows
that 1 per cent, to 4 per cent, of 74 per cent. Calcium Chloride
added to 100 pounds of cement accelerates the hardening
of the concrete to a marked extent.
The American Furniture Mart at Chicago, Illinois. Henry Raeder, Architect, Geo. C.
Nimmons &? Company, and N. Max Dunning, Associates, Wells Brothers Construction
Company, Builders. Solvay Calcium Chloride was used in the concrete.
P. &■ A ■ Pkotn
The world-famous building of the Chicago Tribune at Chicago, Illinois, Howells and
Hood, Architects. R. C. Wiedbolt Company, contractors for the caissons and founda-
tion work, successfully used Solvay Calcium Chloride m all the cement work.
Professor Duff A. Abrams, in charge of the Structural
Materials Research Laboratory of the Lewis Institute, Chi-
cago, Illinois, recently completed a study of the use of Cal-
cium Chloride m concrete. After testing 7500 compression
specimens it was determined that Calcium Chloride pro-
duced an increase in concrete strength as shown by the
COMPARATIVE STRENGTH RATIOS
Treated with 2 to 4%
Calcium Chloride . . .
Under average conditions, concrete that has been treated
with the proper quantity of Calcium Chloride will attain
at the end of 48 hours the strength equal to that of un-
treated concrete after 7 days.
Referring again to the results of Professor Abrams'
study, it is to be noted that it was his conclusion that:
"In the use of Calcium Chloride no advantage was gained
for percentages of the commercial product greater than 2 or
3 per cent., corresponding to a chlorine content of 1 to i}4
per cent. The amount when used m mixes of about 1:5 and
in consistencies suitable for building construction, showed an
increase in strength of from 100 to 200 pounds per square inch.
For richer mixes and drier consistencies the strength in-
crease was greater and for leaner mixes and wetter concretes
it was less. 1 ''
It was also determined that the effect of Calcium Chloride
in cement mortar was essentially the same as in concrete.
Not only is Calcium Chloride of value therefore, in the
actual concrete work, but it is classed by this conclusion
as invaluable to practically all construction work.
The Studio Building. Boston, Massachusetts. W. A. and H. A. Root, Builders.
Solvay Calcium Chloride was used aa accelerator and also as jn jid in prevention of
ireezing in concrete pi j around steel pillars during winter months.
In view of the results of tests and investigations under
actual working conditions, it has been definitely established
that: The quality of the concrete is improved — the strength
is increased with Solvay Calcium Chloride.
With the increasing demonstrations of its value, in con-
nection with concrete work, Calcium Chloride is being
specified by many of America's leading architects and en-
gineers. In fact, a number of the most prominent buildings
recently constructed were completed more quickly through
the use of Solvay Calcium Chloride, with resultant savings
to the owners, and credit to the architects, engineers and
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SOLVAY CALCIUM CHLORIDE ACCELERATES,
STRENGTHENS, AIDS CONCRETE TO RESIST
FREEZING TEMPERATURES AND RENDERS IT
Solvay Calcium Chloride, as a part of the gauging water,
thoroughly permeates the concrete and acts uniformly
throughout the entire mass. In contrast to many integral
materials, which do not dissolve readily in the gauging
water, Solvay is extremely soluble, dissolving almost in-
stantly, resulting in a uniformly finished structure.
This property makes it almost impossible for inexperi-
enced workmen to jeopardise the success of the work. To
produce satisfactory results it is only necessary to add i to
4 pounds of the Calcium Chloride to the gauging water for
each baa of cement.
Tests made by the Bureau of Standards and The Solvay
Process Company prove that Portland Cement, gauged by
a solution of Solvay Calcium Chloride, attains greater
strength in 48 hours than a corresponding mixture with
plain water in 7 days.
With Solvay, finishing is possible within a short time
after pouring the concrete. Concrete placed at 8 o'clock can
be finished by n o'clock. No overtime is required for fin-
ishing concrete placed late in the afternoon — thus effecting
considerable saving of money for the contractor. Further-
more, Solvay-treated concrete sets at the bottom as fast as
at the top, thereby producing a homogeneous mass.
The early strength given to freshly poured concrete pre-
vents the collapse of cell structure during the drying out
period. It increases the crushing, tensile and abrasive
[ 11 1
The Dental Building, Boston, Massachusetts. Architects. McFarLnd and Laurie, Boston.
The front of the building is constructed of cast stone manufactured by the Cambridge
Cement Stone Co. Solvay Calcium Chloride was used to make the cast 6tone.
The final set and strength of the concrete are in no way
adversely affected by the use of Calcium Chloride. In fact,
tests indicate the final strength is increased by its use.
HARDENS AND DENSIFIES
The use of Solvay Calcium Chloride increases the ce-
menting qualities as well as tensile and compression strength
of concrete. Through chemical action concrete is densified
and hardened at the same time, which increases its resist'
ance to dusting.
Concrete or cement mortar gauged with Solvay Calcium
Chloride will absorb considerably less water than when
gauged with plain water. Owing to decreased porosity, the
Solvay-treated concrete is more resistant to wear and also
to acids and alkalies.
These qualities are highly desirable m the construction
of sidewalks and the floors of buildings, particularly fac-
tories, garages, etc. The use of Solvay Calcium Chloride
materially cuts down the usual period of delay experienced
before placing the work in service and decreases mam-
tenance expense by prolonging the life of floor surfaces.
Solvay Calcium Chloride, because it is used integrally,
hardens the entire mass and not just the surface.
COLD WEATHER USE
It is generally recognized that the use of Calcium Chloride
in very cold weather is an absolute necessity inasmuch as
it is impossible to maintain satisfactory working conditions
under the ordinary or "natural 11 method of making concrete.
It is not intended to imply that Calcium Chloride is a
"cure-all 11 for perfect concrete construction under positive
freezing conditions. The fact has been conclusively proven,
however, that Solvay will lower the freezing point of water,
[ 13 1
and therefore of the mix, so that work can proceed into
the cold months of the year and permit concrete to set at
As Solvay hardens the concrete in about half the usual
time, the chance of damage from freezing is naturally cut
The following table gives the recommended proportions
of Solvay to use for different atmospheric temperatures:
+ 28 F.
+ 15 F.
Proportion of Solvay to Water
2 pounds of Solvay to 6 gallons of water
3 pounds of Solvay to 6 gallons of water
4 pounds of Solvay to 6 gallons of water
The above table is based on using approximately 6 gal-
lons of water to each bag of cement.
However, the precautions usually taken to protect con-
crete must be observed. The aggregate and water should
be heated and the concrete covered or otherwise protected.
Thin walls and also concrete subjected to high wind need
greater protection than mass construction.
The Portland Cement Association has published a bul-
letin, "Precautions for Concrete Pavement Construction in
Cold Weather/' The following is taken from this bulletin:
"The only chemical recommended as an addition to the
mixing water is Calcium Chloride. This material possesses
the property of lowering the freezing point of water and
accelerating the setting of the concrete. It is used by being
dissolved in the mixing water. It is generally sold in crys-
talline form and is readily soluble in water."
In a very recent bulletin of the Portland Cement Asso-
ciation it is stated that:
The Commonwealth-Atlantic National Bank Building, Boston, Massachusetts. Geo. W.
Harvey Co., Builders. Solvay Calcium Chloride was used as an accelerator and as an aid
in preventing the freezing of concrete in the mam floor slabs, top finish and in forms around
the steel upright pillars.
"In general the best results in concrete work carried out
in extremely low temperatures will be secured by:
(i) Heating the mixing water and aggregate; aggregate can
best be heated by placing steam coils in the bins.
(2) Protecting the work from wind and snow with canvas or
temporary timber structures and heating interior by
means of steam pipes or salamanders.
(3) Using Calcium Chloride to lower the freezing point of the
mixing water, and to increase the early strength of the
[ 15 1
It is interesting to note in reference to the use of Cal-
cium Chloride in reinforced concrete that it has been demon-
strated that rusting is not progressive on steel completely
embedded in calcium-treated concrete.
Technical News Bulletin No. 75 issued by the Bureau
of Standards, Department of Commerce, Washington, in
commenting on "The Effect of Accelerators on Reinforcing
Steer"' states as follows:
"A number of 1:2:4 concrete and 1:3 mortar specimens
in which steel rods have been embedded were broken dur-
ing the past month, and an examination made of the rods.
Calcium Chloride solutions had been used for some of the
specimens as the gauging liquid. An examination was also
made of expanded metal which had been embedded in small
slabs prepared from mortar gauged with a proprietary
compound of the accelerator type.
Some of the foregoing specimens were five and others six
years old and all had been stored out of doors and exposed
to the weather. From this examination it is concluded that
while Calcium Chloride tends to corrode the reinforce-
ment, the corrosion does not seem serious or of a progressive
nature with age, in cases where the reinforcement is com-
pletely embedded in the concrete. However, when using
accelerators, care should be taken to completely coat and
embed the reinforcement and avoid pockets near it."
The integral method of water-proofing concrete has been
found to be the best, and is highly favored by engineers
and contractors. The action of Solvay Calcium Chloride in
accelerating early hardening gives strength to the concrete,
preventing the collapse of the cell structure during the
evaporation of the water. Porosity is thus reduced to a mini-
mum and the concrete rendered dense and more water-proof.
Solvay has a lubricating action on the cement, due, it is
believed, to increasing the solubility of the silicates present.
This causes the concrete or cement mortar to become more
plastic and workable. Workmen like this "fatty 1 ' mix be-
cause it means quicker work and easier troweling conditions.
As a result the particles are cemented together, producing
a smooth surface which is much more water-proof than one
obtained with untreated concrete.
Boston Chamber of Commerce Building, Boston, Massachusetts. \V. M. Evatt Company,
Builders. Solvay Calcium Chloride was used in the main floor slabs set during winter
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DIRECTIONS FOR USING SOLVAY
The directions for using Solvay Calcium Chloride are
so simple that it is possible to have the work done through'
out by ordinary labor. It is important to remember that for
best results not less than i pound nor more than 4 pounds
of Calcium Chloride should be used to each bag of cement,
except for free^e-resisting use, when up to 6 pounds can
be used if necessary.
To make up a standard solution of Solvay Calcium
Chloride, fill a barrel, or other suitable container, in the
proportion of two pails of water for each pail of Solvay,
stirring until the Calcium Chloride is completely dissolved.
The mixture will contain the following quantity of Calcium
1 gallon 3.2 pounds of Calcium Chloride
1 quarts 2.4 pounds of Calcium Chloride
2 quarts 1.6 pounds of Calcium Chloride
1 quart 0.8 pound of Calcium Chloride
Then mix the batch of concrete or cement mortar just
as you have been in the habit of doing, except that for each
bag of cement used add about 3 quarts of standard Solvay
Calcium Chloride solution together with the necessary
water. This quantity can be increased or decreased as needs
require. Experience will doubtless suggest other methods
for using Solvay, but the above is simple in practice and
efficient in operation.
USED AFFECT RESULTS?
Solvay Calcium Chloride may be used with any brand
of Portland Cement, although the results obtained by the
use of Calcium Chloride with different brands will vary to
a slight extent.
[ 18 l
The new addition to the Boston Storage Warehouse, Boston, Massachusetts. W. M. Evatt
Co., Builders. Solvay Calcium Chloride was used in the walls, floors, etc.. during the winter
With most brands of Portland Cement the proper amount
for general purposes is i pounds of Solvay Calcium Chloride
to each bag of cement. Should this proportion not give
the desired results, the amount may be slightly diminished
or increased to suit requirements.
In his most recent work Professor Abrams pointed out
that the various brands used in his tests were in general
similarly affected by the addition of Calcium Chloride.
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The Meyer: rd Building, Chicago, Illinois. Mr. F. T. Bear, Contractor. Solvay Calcium
Chloride used in the walls and floors.
AMOUNT TO BE USED AND COST
It has usually proven most satisfactory to use the quan-
tity of cement going into each batch as a basis to determine
the necessary amount of Calcium Chloride. Increasing the
quantity of Calcium Chloride accelerates the initial harden-
Solvay Calcium Chloride east of the Mississippi costs
approximately two cents per pound. In the Far West the
cost will be slightly higher. The cost of using Solvay is
small considering the time and labor saved and the better
The quantity required for a given job can generally be
estimated by figuring 2 pounds of Calcium Chloride to each
bag of cement. The amount actually required on the job
will depend on prevailing conditions, such as temperature,
location, kind of mix, etc.
Solvay Calcium Chloride is shipped m non-returnable
metal drums for which no additional charge is made. These
standard drums contain 375 pounds net each. Solvay is
also shipped in moisture-proof, paper-lined, burlap bags,
containing 100 pounds net each. Calcium Chloride in bags
requires the same weather protection as cement. The ease
of handling the bags makes this container very attractive
to many customers.
The Solvay Process Company carries stock of Solvay
Calcium Chloride in more than 75 cities in the United
States, which insures prompt service with minimum trans-
portation charges. In carload shipments direct from the
plant the Traffic Department of the Company is especially
equipped and prepared to facilitate delivery safely and
The Park Square Building, Boston, Massachusetts. Densmore, LeClear and Robbins,
Architects, W. A. and H. A. Root, Builders. Solvay Calcium Chloride was used in cement
mortar and in cement finish of all floors. $6,000 was actually saved in labor in placing
floor finish through the use of Solvay Calcium Chloride.
[ 21 ]
It is quite natural that in specific instances problems will
arise relative to the use of Solvay Calcium Chloride, and
while it has been the intent to give full particulars in this
booklet, unusual conditions call for special treatment.
With this in mind The Solvay Process Company desires
that architects, engineers and contractors avail themselves
of the facilities of its Technical Service Department. This
service is gratis and gladly extended in the interests of
Better Concrete Construction.
THE SOLVAY PROCESS COMPANY
Wing fe? Evans, Inc., Sales Department
40 RECTOR STREET, NEW YORK, N. Y.
v mg part of the [it of The S Process Com pu itSyracua
Other pbnts are located at Detroit, Michigan and Hut neon, ^ insae.
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